Engineering · Manufacturing · Service

Marine Propeller Technical Guide

The right propeller is the result of evaluating the vessel, engine, gearbox and real operating profile together. Explore the key terms, product programme and decisions that lead to manufacture.

Explore 28 models Run a preliminary calculation
2–7Blade fixed-pitch propeller production
100–2500Millimetre project-production diameter range
7 / 28Standard series / technical model entries
50+Years of marine manufacturing experience
01 — The right starting point

Propeller selection is not one dimension

The performance of a ship or boat propeller cannot be explained by diameter or blade count alone. Vessel type, length, beam, draft and displacement; target service speed; engine power and rated rpm; gearbox reduction; shaft rotation; available aperture and the duty cycle are parts of one engineering problem. A fishing vessel that prioritises thrust does not share the same design priorities as a high-speed craft approaching cavitation limits.

These inputs allow diameter, pitch, P/D ratio, blade number, developed blade-area ratio, rake and skew to be assessed together. Missing or estimated data may produce an engine that cannot reach rated rpm, overload, vibration, higher fuel use or insufficient thrust. The Propeller Calculator provides a preliminary result; the result should still be reviewed against verified project data before manufacture.

Core information for an engineering quotation

Vessel type and dimensions, displacement, engine make/model, power and maximum rpm, gearbox ratio, shaft rotation, current propeller diameter–pitch–blade data, target speed and the vessel's dominant operating condition.

02 — Product programme

A series for each operating profile

The Eriş standard programme groups 7 series and 28 technical models for bow-thruster, medium- and high-speed, pleasure craft, gulet, fishing vessel, tug, nozzle and sailing applications. Published ranges define each model family; final diameter and pitch depend on the vessel's verified project data.

Bow Propeller Series bronze propeller 4 models

Bow Propeller Series

Three- and four-blade fixed-pitch propellers for tunnel-type bow thrusters.

 E Series bronze propeller 4 models

E Series

High blade-area fixed-pitch propellers for medium- and high-speed applications.

 R Series bronze propeller 4 models

R Series

The EP-20 family for gulets, pleasure craft, fishing vessels and tug applications.

 S Series bronze propeller 4 models

S Series

The EP-30 family covering medium/high-speed, fishing/tug and project-specific applications.

 C Series bronze propeller 4 models

C Series

The four- and five-blade CP-70 family for medium- and high-speed operating profiles.

 Kaplan Series bronze propeller 4 models

Kaplan Series

Kaplan geometry for tugs and fishing vessels requiring high thrust in nozzle duty.

 Sailing Series bronze propeller 4 models

Sailing Series

Narrow-blade, two-blade YP-50 fixed-pitch propellers for low drag under sail.
By vessel application

Blade geometry matched to vessel duty

Two propellers with the same diameter and blade count may behave differently because their blade area and section geometry differ. Displacement, hull form, service speed and dominant duty together define the priorities for strength, thrust, manoeuvrability, vibration and efficiency.

01

Commercial and pleasure-vessel propellers

Eriş Propellers offers different three-, four- and five-blade geometries for pleasure and charter boats, sea taxis, sweeper vessels, ambulance boats and similar workboats. Semi-elliptical or ogival blade sections may be considered according to hull form and displacement. Designs with a wider-than-standard blade area are used where heavy-duty operation requires greater load-carrying capability and thrust.

Explore commercial-vessel models

Design objectives

  • High strength
  • Increased blade area
  • Efficient blade geometry
  • Long service life
  • Smooth, balanced operation
  • High thrust for different workboat duties
02

Fishing vessels

For trawlers, shrimp boats and similar fishing vessels, the main propeller objectives are high low-speed thrust, manoeuvrability, smooth running and fuel economy. Rake, skew, blade area and engine loading must be assessed together rather than selecting from diameter or pitch alone.

Explore fishing and commercial-vessel models
03

Yacht and performance craft

For motor yachts, superyachts, ferries and high-powered craft, vibration, noise and manoeuvring behaviour matter alongside speed. Raked and skewed blade geometries are engineered together with available clearance, engine power and target rpm.

Explore yacht propellers and performance models
04

Sailing vessels and gulets

Narrow-blade fixed-pitch geometries are used where low drag under sail is a priority. Diameter and pitch are balanced to retain adequate motoring thrust and safe engine loading without overlooking sailing performance.

Explore sailing-vessel and gulet models
05

Kaplan, nozzle and heavy-duty applications

Kaplan-type propellers are evaluated for the high-thrust requirements of tugs, heavy-duty vessels and net-fishing boats. Nozzle operation introduces different loading from an open propeller, so blade-tip and skew geometry are engineered for smooth operation with reduced vibration.

Explore Kaplan and heavy-duty models
03 — Essential terms

Diameter, pitch and blade geometry

Reading a technical table correctly helps explain why two visually similar propellers can behave differently. The parameters below are not independent: changing one can require the other values and the expected vessel response to be reassessed.

Diameter
The diameter of the circle swept by the blade tips. It affects thrust capacity, tip speed and the physical clearance required under the hull.
Pitch
The theoretical distance travelled in one revolution with no slip. It must be evaluated with engine loading and achieved rpm.
P/D
The pitch-to-diameter ratio. It helps compare the geometric loading character of propellers with different diameters.
DAR
Developed blade area divided by propeller disc area. It is closely related to cavitation margin, load capacity and blade number.
Rake
The axial inclination of the blades relative to the propeller plane. It influences clearance, loading distribution and hydrodynamic behaviour.
Skew
The circumferential sweep of the blade form. It can influence load transition, vibration and noise behaviour.

Model-specific diameter, P/D, blade-area ratio, rake, skew and ISO 484 Class II tolerance data, together with hub, taper, keyway and shaft dimensions, are available on the related technical pages. Propeller models → Technical dimension tables →

04 — Material and production

From calculation to a balanced product

Manganese bronze and nickel-aluminium bronze (Nibral) are evaluated against strength, corrosion behaviour, castability and repair requirements for marine propellers. Material is not selected by appearance: diameter, loading, service environment and the project specification all matter.

The Eriş workflow starts with engineering and CAD/CAM preparation, then continues through pattern and mould work, casting in an electric furnace with up to 2500 kg capacity, CNC machining, finishing, dimensional inspection and static balancing. Product geometry and the required tolerance class are confirmed before manufacture according to project scope.

Project data

Vessel, engine, gearbox and operating targets are verified.

Design

Diameter, pitch, blade geometry and material pass engineering review.

Manufacture

Pattern, mould, casting, CNC machining and precise finishing are applied.

Inspection

Dimensions, surface, pitch distribution and static balance are checked.

05 — Service decision

Repair or replacement?

A bent blade, missing edge, crack, impact, corrosion, cavitation mark, pitch inconsistency and balance error do not receive the same treatment. It is not responsible to declare a propeller repairable—or condemn it—before considering the material, damage location, extent and previous repair history. Visual inspection should be supported by dimensional measurement, crack inspection, pitch checking and material assessment when needed.

Suitable damage may be addressed through correction, welding, re-machining, finishing and balancing. When structural integrity or target geometry cannot be recovered with confidence, replacement is the safer route. Review the related service and technical journal pages, or send photographs and verified project information for an engineering assessment.

ManufacturingCAD/CAM, casting and CNC capability → SystemsShaft, steering, bow thrusters and anodes → Technical journalPropeller engineering articles → Models7 series and 28 technical models → DimensionsHub, shaft and keyway tables → Your projectRequest an engineering review →